Chuck



Aug. 8, 1933. E, A. NORMAND CHUCK Filed May 5l, 1932 INVENTOR.

H/S ATTORNEY Patented Aug. s, 1933 UNITED STATESg CHUCK Ernest A. Normand, San Francisco,

Calif., t

, assignor to Emile H. Normand, San Francisco,

Calif.

Application May s1, 1932. serial No. 614,486

1 claim. (ol. 279-75) My invention relates to a chuck. and Darticularly to a chuck for gripping a uted tool. It is among the objects of my invention to provide a chuck having improved locking means 5K5 for engaging the uted shank of a tool, such as a twist drill.

Another object of my invention is to provide a chuck of the character described which will receive tools of different size.

. tool may center. f vided, and is mounted on the' holder to project A further object of my invention includes the provision, in a chuck of the character described, of means for accurately and automatically centering the tool. l

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of my invention. It is to be understood that I do not limit myself to this disvclosure of species of my invention, as I may adopt variant embodiments thereof within the scope of the claim.

Referring to the drawing:

Figure 1 is a side view, partly in section and partly in elevation showing a chuck embodying the improvements of my invention; and

Figure 2 is a transverse vertical sectional view of the same taken in a plane indicated by the line 2 2 of.Figure 1.

In terms of broad inclusion, the chuck embodying my invention comprises a recessed holder for receiving the shank of a fluted tool. The holder is preferably provided with a conical seat at the base of the recess in which the end of the A locking element is also prointo the recess for engaging a flute in the tool. Preferably a pair of the locking elements are provided and are oppositely disposed inthe holder, and means are preferably provided for ,pressing the elements toward each other and into clamping engagement with the tool to lock the same and center it axially of the recess.`

Resilient means are also preferably provided for spreading the locking elements to hold the same for selectivelyvarying the length of tool projecting from the chuck.v

In greater'detail, `the preferred form of ,chuckl embodying my invention comprises a holder having a shank portion 2 and a headrportion 3; the

securely held.V Means are also preferably provided in the chuck to provide a recess 4 for receiving the fluted end of a tool, such as a broken twist drill. The shank end of the holder is preferably slotted, and is threaded to receive a plug 6 having a conical seat 7 in which the end of the tool may center. The purpose of making the plug 6 adjustable is to provide means for varying the depth of the recess 4; it being understood that the length of tool projecting from the chuck may be varied by turning the adjusting plug 6. When the holder is clamped in a machine the plug is A securely locked in the slotted shank portion 2 of the holder.

The head portion 3 of the holder is preferably cross drilled to provide a pair of oppositely disposed apertures 8 opening into the recess 4. A

locking element, preferably inthe `nature of a.

ball 9, is seated in each of the apertures 8, and

projects into the recess for engaging a flute in the` 'niL These springs engage the balls and operate to` urge them outwardly of the recess.

Means are also provided for adjusting the lockingelements or balls 9 relative to the amount of their separation, so that the balls may be forced toward' eachV other against the action of the springs llrand into the clamping engagement with the tool for preventing the same from dropping out of the chuck. This adjusting means .is preferably designed to move the balls 9` simultaneously and equally, so that the balls not only serve to lock and` clamp the tool, but also function vto center the tool axially of the holder.

To accomplishthese results the chuck head 3 is preferably tapered, and a sleeve 12, having a and center thetool, and by turning the sleeve in the oppositeY direction the balls are allowed to separate to permitready removal of the tool.VV

The spreading of the balls 9 and their varying engagement in the iiutes vof different sized tools holder being preferably tubular in construction adapts `the chuck for receiving `a convenient range of tool sizes. For example, I have designed a chuck in accordance with the teachings of my invention that will take twist drills ranging in size from 1A; to 1@ inch.

I claim:

A chuck for gripping a fluted tool comprising a recessed holder for receiving the tool and having an aperture opening into the recess, a ball los 

